Uso de enzimas digestivas y ácidos biliares obtenidos de oreochromis sp aplicados en cultivos de penaeus vannamei a baja salinidad

Abstract

Aquaculture is an industry that is developed on a large scale within the country, mainly it dedicated to the white shrimp Penaeus vannamei cultivation. Due to market demand, shrimp production has exponential growth, in order to satisfy it. These are the reasons that different investigations are carried out, to find procedures capable of improving the performance of the producing farms, as well as innovations or strategies to stimulate shrimp growth and resistance to diseases that can cause high mortality rates, obtaining significant losses to the producer. In the last years, shrimp farming has begun to be developed in low salinity, due to the economic lands prices, and its accessibility. In addition, the water with low salinity exhibits less growth of pathogens in compared with water with salinity above 25 ppt. To produce on low salinity, the producers avoid elevated losses in production. However, these crops suffer an ionic imbalance, which if it was not controlled it can harm the development of the animals. The ionic imbalance can be corrected by Ca, K and Mg ions application, which are the most important for the development animals. And physiological processes of organisms. It is relevant to noted that the systems allowed to maintain a higher density of shrimp per m2 if the physicochemical parameters of the water are stable. It could say that in most shrimp farms with less salinity waters, it is possible to practice a semi-intensive or intensive farming system, which allows them to obtain a higher production in a reduced space. The use of different substances, natural or chemical, in order to promote growth and reduce the bacterial load within shrimp in shorter periods of time, is the objective of several investigations carried out by companies dedicated to the production and sale of aquaculture supplies. Examples of these substances are bile acids and digestive enzymes that are involved in the shrimp digestibility, and it is possible that they can also improve the assimilation of nutrients within the body, stimulating the growth process. For the aforementioned, this investigation aims to evaluate the effect of natural digestive enzymes and bile acids extracted from tilapia Oreochromis sp, on the growth and amount of white shrimp total bacteria. For the experimentation, 3 treatments were tested in shrimp feeding: T1 (bile acids), T2 (digestive enzymes) and a control treatment with a dosage of 1g/Kg of food. Each treatments had three repetitions during a period of 28 days with two daily applications. For the experimentation, it was used 135 specimens of P. vannamei, which were produced with an average weight of 3gr, and were distributed homogeneously in 9 drawers with a volume of 30 L with constant aeration. The water parameters were constant and the same for all treatments, replacing of water periodically each 48 hours and applying bacteria and mineral salts daily. At the end of this period, microbiological analyzes were carried out in Nutrient Agar, to determine the number of total bacteria (CFU/ml) in the organism. Through of the inter-group analysis of variance (ANOVA), it was determined that there were not significant differences between treatments in terms of growth, however, digestive enzymes had a greater effect on bacterial load compared to the control treatment, and a similarity with billiard acids. In conclusion, the mixture of digestive enzymes has a greater effect on biomass and bacterial load in relation to bile acids and control, however, they do not present significant differences with respect to the final biomass of T1 and control treatments.